Acylation is a key step in the manufacture of intermediates in the fine chemical and pharmaceutical industry. The Friedel Craft acylation is a step that can be used in the production of such pharmaceutical compounds as (S)-naproxen (1) and ibuprofen (2). 
For example, the acylation of 2-methoxynaphthalene (2 MN) in the presence of aluminum chloride was a step in the first large-scale synthesis of naproxen and the acylation of isobutylbenzene with hydrogen fluoride as catalyst is currently used in the synthesis of ibuprofen. Because of current environmental restrictions, replacement of conventional homogeneous catalysts with solid acid catalysts has great industrial importance. Zeolites, with their shape selective properties and good regenerability, have been found to be viable alternatives to liquid acids in numerous cases. A recent study shows the first industrial application of a zeolite promoted acylation for the production of an aromatic ketone.
The acetylation of 2 MN has been investigated over MCM-41, HY, ZSM-12 and *BEA, and ZSM-5 and mordenite. Two products are usually obtained, 1-acetyl-2-methoxynaphthalene (1,2-AMN and 2-acetyl-6 methoxynaphthalene (2,6-AMN), with the undesired 1,2-AMN product generally predominating. Indeed, the acylation generally occurs at the kinetically favored 1-position. However, the deacylation of the acyl group has been observed to give back 2MN. These results are consistent with the following reaction as shown in Scheme 1: 
It would therefore be advantageous to identify materials and methods that can be used to improve the yield of desired organic groups in acylation reactions, particularly those catalyzed using zeolite beta. This would be particularly useful in the pharmaceutical industry as it would provide a viable acylation catalyst for the formation of precursors to, for example, the nonsteroidal anti-inflammatory agent, naproxen.
This invention comprises a process for the shape selective acylation of an organic compound, the process comprising the steps of reducing the number of surface acid sites on at least a portion of the surface of a zeolite, and acylating the organic compound in the presence of the zeolite. The organic compounds include, for example, olefins, aromatic hydrocarbons, phenolic compounds, and heterocyclic compounds, wherein the organic group may be substituted or unsubstituted. The zeolite may be any synthetic zeolite with a unidimensional, two-dimensional, or three-dimensional network, or any molecular sieve with structural features similar to these. The acylation may occur in the presence of an acylating agent. Such acylating agents include, for example, halides of aliphatic carboxylic acids and the anhydrides of carboxylic acids.